What determines the size of a shark and how large can they grow?
The liver is the key organ which determines the overall length of a shark, and it is filled with oil that is lighter than sea water. Livers from some of the largest whales weigh 200 pounds and contain more than 18 gallons of oil! Because sharks are the muscle machines (unlike the ‘blubbery’ humpbacks who use their blubber for buoyancy) – how is it that they can float? While most other types of fishes have a swim bladder which they fill with air for buoyancy; the shark has adapted its liver and specifically the liver oil. But there are limitations to how much room the liver can have within the body cavity of the shark which has other important organs to house as well. Thus, the liver can only be so large, and it limits the overall size of the shark. Cool Facts (summarized from MARMAM, an internet e-mail group): “Sea Lions Trained to Film & Tag Whales”, Researchers are training sea lions to become their spies of the deep. A 400-pound, 17-year-old male named Beaver and his 190-pound, eigh
